Only copy the required xcasset files into the user bundle

Before all xcassets used in pod sources where unconditionally integrated into the bundle's car file, even if the xcasset file wasn't referenced by the podspec. Now only files, which are explicitly specified in the spec, will be integrated.

lib/cocoapods/generator/copy_resources_script.rb

@@ -96,6 +96,8 @@ mkdir -p "${CONFIGURATION_BUILD_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}"
 RESOURCES_TO_COPY=${PODS_ROOT}/resources-to-copy-${TARGETNAME}.txt
 > "$RESOURCES_TO_COPY"
 
+XCASSET_FILES=""
+
 install_resource()
 {
   case $1 in
@@ -126,6 +128,7 @@ install_resource()
       xcrun mapc "${PODS_ROOT}/$1" "${CONFIGURATION_BUILD_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}/`basename "$1" .xcmappingmodel`.cdm"
       ;;
     *.xcassets)
+      XCASSET_FILES="$XCASSET_FILES '$1'"
       ;;
     /*)
       echo "$1"
@@ -150,7 +153,7 @@ EOS
 
       XCASSETS_COMPILE = <<EOS
 
-if [[ -n "${WRAPPER_EXTENSION}" ]] && [ "`xcrun --find actool`" ] && [ `find . -name '*.xcassets' | wc -l` -ne 0 ]
+if [[ -n "${WRAPPER_EXTENSION}" ]] && [ "`xcrun --find actool`" ] && [ -n $XCASSET_FILES ]
 then
   case "${TARGETED_DEVICE_FAMILY}" in
     1,2)
@@ -166,7 +169,7 @@ then
       TARGET_DEVICE_ARGS="--target-device mac"
       ;;
   esac
-  find "${PWD}" -name "*.xcassets" -print0 | xargs -0 actool --output-format human-readable-text --notices --warnings --platform "${PLATFORM_NAME}" --minimum-deployment-target "${IPHONEOS_DEPLOYMENT_TARGET}" ${TARGET_DEVICE_ARGS} --compress-pngs --compile "${BUILT_PRODUCTS_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}"
+  echo $XCASSET_FILES | xargs actool --output-format human-readable-text --notices --warnings --platform "${PLATFORM_NAME}" --minimum-deployment-target "${IPHONEOS_DEPLOYMENT_TARGET}" ${TARGET_DEVICE_ARGS} --compress-pngs --compile "${BUILT_PRODUCTS_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}"
 fi
 EOS
     end